GTEs convert the potential energy associated with air and fuel into energy primarily in the form of mechanical rotation and heat. A conventional GTE may include a compressor assembly, a combustor assembly, and a turbine assembly. During operation, air is drawn into the compressor assembly, where it is compressed and supplied to the combustor assembly. The combustor assembly supplies fuel to the compressed air and ignites the compressed air and fuel, resulting in combustion, which increases the energy associated with the compressed air. The combustion products are supplied to the turbine assembly, where expansion of the combustion products through the turbine assembly causes a turbine rotor to rotate. A compressor rotor of the compressor assembly and the turbine rotor may be coupled to one another via a shaft, such that rotation of the turbine rotor causes rotation of the compressor rotor. The turbine rotor may also be coupled to one or more systems that use the rotational energy and/or thermal energy from the turbine assembly. For example, a GTE may be used to supply power to machines, such as airplanes, locomotives, boats, ships, trucks, automobiles, electric generators, pumps, or other machines configured to perform work.
During operation, an assembly including the compressor and turbine rotors may rotate at 10,000 or more revolutions per minute, and thus, it may be desirable to balance the rotating assembly in order to prevent excessive vibration during operation of the GTE. One solution for facilitating balancing of the rotating assembly includes coupling a band to the rotating assembly. The band may include a system for attaching one or more weights to the band at different radial locations about the band in order to improve the balance of the rotating assembly. However, by virtue of being coupled to the rotating assembly of the GTE, it may be difficult to gain access to the band because the rotating assembly may be located inside an outer case of the GTE.
A method and apparatus for trim balancing a GTE is disclosed in U.S. Pat. No. 5,545,010 issued to Cederwall et al. (“the '010 patent”). In particular, the '010 patent discloses a method and apparatus that allows a GTE to be balanced with the outer case in situ. Access to a rotor of the GTE from the exterior of the outer case is obtained via the intake opening of the compressor air flow path and a pair of holes that may be sealed using a pair of removable plugs. The '010 patent discloses removing the plugs to obtain access to a band coupled to the rotor, such that balancing can be performed by adding or removing weights or plugs to the band.
Although the method and apparatus disclosed in the '010 patent may permit balancing of the rotor, they may suffer from a number of possible drawbacks. For example, the removable plugs may only be accessed via the intake opening of the compressor air flow path. For some GTEs, it may be desirable to provide a band at a location remote from the intake opening. In addition, providing the band at a location of the rotor remote from the rotor vanes and stator vanes of the compressor assembly may add to the length of the GTE. This may be undesirable for a number of reasons. For example, it may be desirable to reduce the footprint of the GTE, thereby rendering it potentially undesirable to add to the length of the compressor section by virtue of providing space for the band.
The methods and systems described in an exemplary manner in the present disclosure may be directed to mitigating or overcoming one or more of the potential drawbacks set forth above.